Highway advisory signs throughout the state of Victoria (and, indeed, Australia) warn of 'wildlife crossing ahead' or similar words, often with a pictogram of an animal. These advisory signs are commonly on 100 km/h limited roads.
This is an acknowledgement of the threat to wildlife posed by traffic. It would be reasonable to give legal effect to these warnings by lowering speed limits to, say 80 km/h (or even less depending on circumstances) for the extent of the road where wildlife is known to cross. A precedent exists with reduced speed limits for school zones.